CN106838193B

CN106838193B - Four-channel torque converter

Info

Publication number: CN106838193B
Application number: CN201610991853.5A
Authority: CN
Inventors: 杰夫瑞·爱德华·毛瑞尔; 格雷戈里·丹尼尔·格莱斯基; 戴维·艾伦·贾森
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2015-11-10
Filing date: 2016-11-10
Publication date: 2021-05-25
Anticipated expiration: 2036-11-10
Also published as: CN106838193A; US20170130812A1; US9915330B2

Abstract

A four-channel torque converter is disclosed. A torque converter uses four different fluid passages. The torque converter chamber is supplied with fluid via a passage that includes a gap between a guide axle insert and a turbine axle. Fluid is returned from the hydraulic chamber via a passage formed between the hollow idler shaft and the idler shaft insert. The torque converter includes a bypass clutch having an apply chamber and a return chamber. Fluid is delivered to the application chamber via a passage comprising a gap between the hollow portion of the turbine shaft and the turbine shaft insert. Fluid is delivered between the balance chamber and the high-level discharge port via a passage that travels through the turbine shaft insert.

Description

Four-channel torque converter

Technical Field

The present disclosure relates to the field of automatic transmissions for motor vehicles. More specifically, the present disclosure relates to a transmission having four fluid passages leading to a torque converter.

Background

Many vehicles are used over a wide range of vehicle speeds, including both forward and reverse motion. However, certain types of engines can only operate efficiently over a narrow speed range. Therefore, a transmission capable of transmitting power at a plurality of gear ratios with high efficiency is often used. When the vehicle is at low speeds, the transmission is typically operated at a high gear ratio such that the engine torque is multiplied to increase acceleration. Operating the transmission at low gear ratios allows engine speeds associated with quiet, fuel efficient cruising when at high vehicle speeds.

Fig. 1 shows a powertrain 10 having a transmission 12. The solid lines indicate mechanical power flow and the dashed lines indicate information signal flow that may be transmitted electrically or hydraulically. Power is generated by the engine 14 and is transmitted to the transmission input shaft 16. The torque converter 18 and gearbox 20 modify the speed and torque of the delivered power to match vehicle demands while allowing the engine 14 to operate at the proper crankshaft speed. Power flows from the torque converter to the gear box via the turbine shaft 22. Drive shaft 24 transfers power from transmission 12 to differential 26. Differential 26 distributes power between

drive wheels

28 and 30 while allowing a slight difference in rotational speed (such as during cornering). Some transmissions (such as front wheel drive axles) may include a differential in the same housing as the gearbox and torque converter. In such transmissions, power may be transmitted to the differential using a gear or chain that is distinct from the drive shaft. In some vehicles, a transfer case may be placed between the transmission and the differential to transfer some power to the other wheels.

The transmission controller 32 adjusts the state of the transmission 12 based on various inputs, including vehicle speed measurements, driver torque demand as indicated by accelerator pedal position, and a shift selector. The controller 32 may adjust the state of the transmission by sending an electrical signal to the valve body 34. In response to these signals, the valve body 34 regulates the pressure in the hydraulic circuit to engage a particular clutch (such as a clutch within the gearbox 20 and a bypass clutch within the torque converter 18).

Fig. 2 schematically illustrates the torque converter 18. The impeller 40 is fixed to the input shaft 16 and is supported by a transmission housing 42. In operation, the space enclosed by these components is filled with transmission fluid. The turbine shaft 22 is drivably connected to a turbine 44. A torsional damper may be interposed between the turbine 44 and the turbine shaft 22 to isolate the gearbox 20 and other drive train components from engine vibrations. The stator 46 is coupled to the transmission housing 42 via a one-way clutch 48. The one-way clutch 48 holds the stator 46 stationary while the turbine shaft is stationary or rotating slowly relative to the transmission input shaft 16. Rotation of the impeller 40 forces fluid to flow between the impeller, turbine and stator. The fluid exerts a hydrodynamic torque on the turbine 44. The stator 46 provides a reaction force so that the torque on the turbine 44 can be greater than the torque on the pump 40. As the speed of turbine 44 approaches the speed of pump 40, fluid tends to flow about centerline 50, overrunning (overrunning) one-way clutch 48. The chamber 52, which includes the turbine, impeller and stator, is referred to as a hydrodynamic chamber.

To improve power transfer efficiency, once the vehicle reaches sufficient speed, the controller may engage the bypass clutch 54 to selectively connect the transmission input shaft 16 to the turbine shaft 22. The clutch assembly 56 includes one or more discs that rotate with the input shaft 16 interleaved with one or more discs that rotate with the turbine shaft 22. To engage the clutch, pressurized fluid is delivered to the apply chamber 58, forcing the piston 60 against the clutch pack 56. When the pressure is released, the spring 62 forces the piston 60 away from the clutch assembly. The fluid pressure in the balance chamber 64 also tends to urge the piston 60 away from the clutch pack 56. The balance chamber 64 may be filled with a low pressure fluid to counteract the pressurization of the fluid caused by centrifugal forces. The controller may partially apply the clutch 54 so that the difference in rotational speed between the input shaft 16 and the turbine shaft 22, referred to as slip, is a desired amount. During partial clutch application, some torque is transmitted through the clutch 54, while the remainder of the input torque is transmitted hydraulically via the impeller, stator, and turbine. Precise control of the torque capacity of the clutch 54 is required to maintain the desired slip.

Disclosure of Invention

A transmission includes a torque converter, a front support, a hollow idler shaft, a one-way clutch, a hollow idler shaft insert, a hollow turbine shaft, and a hollow turbine shaft support. The torque converter includes a pump impeller, a turbine impeller, and a stator impeller. The torque converter may also include a bypass clutch configured to selectively connect the impeller to the turbine. The front support defines four fluid channels, which may be located at the same axial position. The valve body may supply fluid to the torque converter via the second fluid passage and receive fluid from the torque converter via the first fluid passage. The idler is connected to the front support via a one-way clutch and a hollow idler shaft. The first fluid passage of the front support is fluidly connected to the gap between the idler shaft and the idler shaft insert. A turbine shaft is drivably connected to the turbine and extends through the guide axle insert. The second fluid passage is fluidly connected to a gap between the guide axle insert and the turbine axle. The third fluid passage is fluidly coupled to a gap between the turbine shaft and the turbine shaft insert. The fourth fluid passage is fluidly coupled to an interior of the turbine shaft insert. The third fluid passage may be fluidly connected to the apply chamber of the bypass clutch and the fourth fluid passage may be fluidly connected to the balance chamber of the bypass clutch. The fourth fluid passage may also be fluidly connected to a high-level drain.

According to the present invention, there is provided a transmission comprising: a torque converter having a clutch assembly and a hydraulic chamber; a stator support defining a first axial passage fluidly connected to the hydraulic chamber; a turbine shaft supported for rotation within the stator support and defining second and third axial passages fluidly connected to the clutch assembly, a space between the stator support and the turbine shaft forming a fourth axial passage fluidly connected to the hydraulic chamber.

According to one embodiment of the present invention, the transmission further includes a front support fixed to the idler support and defining four radial channels fluidly connected to one of the first, second, third, and fourth axial channels, respectively.

According to one embodiment of the invention, the four radial channels are located at the same axial position relative to the axis of the stator support and are circumferentially spaced.

According to one embodiment of the invention, the transmission further comprises a valve body fluidly connected to at least three of the four radial passages.

According to one embodiment of the invention, the valve body is configured to supply transmission fluid to the hydraulic chamber via the fourth axial passage and to receive transmission fluid from the hydraulic chamber via the first axial passage.

According to one embodiment of the invention, the clutch assembly defines an apply chamber fluidly connected to the second axial passage and a balance chamber fluidly connected to the third axial passage.

According to one embodiment of the invention, the balance chamber is fluidly connected to the hydraulic chamber through an orifice.

According to one embodiment of the invention, the third axial passage is fluidly connected to the high-level discharge port.

According to one embodiment of the invention, the turbine shaft comprises a hollow insert located within the hollow portion of the outer shaft, the interior of the hollow insert forming one of the second and third axial passages, the space between the insert and the outer shaft forming the other of the second and third axial passages.

According to one embodiment of the present disclosure, the idler support includes a hollow insert within a hollow outer shaft, the space between the insert and the outer shaft forming a first axial passage.

According to the present invention, there is provided a transmission comprising: a front support defining a first fluid passage, a second fluid passage, a third fluid passage, and a fourth fluid passage; a hollow guide axle fixed to the front support; a hollow idler shaft insert secured to an interior of the idler shaft, a first fluid passage fluidly connected to a gap between the idler shaft and the idler shaft insert; a hollow turbine shaft extending through the guide axle insert, a second fluid passage fluidly connected to a gap between the guide axle insert and the turbine shaft; and a hollow turbine shaft insert secured to an interior of the turbine shaft, a third fluid passage fluidly connected to a gap between the turbine shaft and the turbine shaft insert, and a fourth fluid passage fluidly connected to the interior of the turbine shaft insert.

According to one embodiment of the present invention, the transmission further includes a torque converter having a clutch assembly and a hydrodynamic chamber, the hydrodynamic chamber being fluidly connected to the first fluid passage and the second fluid passage, the clutch assembly defining an apply chamber fluidly connected to the third fluid passage and a balance chamber fluidly connected to the fourth fluid passage.

According to one embodiment of the invention, the four fluid passages are located at the same axial position relative to the axis of the turbine shaft and are circumferentially spaced.

Drawings

FIG. 1 is a schematic diagram of a vehicle powertrain.

FIG. 2 is a schematic illustration of a torque converter suitable for use in the powertrain of FIG. 1.

Fig. 3 is a cross section of a front transmission support.

FIG. 4 is a first cross-section of a center portion of the torque converter assembly.

FIG. 5 is a second cross-section of the center portion of the torque converter assembly.

FIG. 6 is a third cross-section of a center portion of the torque converter assembly.

Detailed Description

Embodiments of the present disclosure are described herein. However, it is to be understood that the disclosed embodiments are merely exemplary and that other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As one of ordinary skill in the art will appreciate, various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combination of features shown provides a representative embodiment for a typical application. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desired for particular applications or implementations.

Fig. 3 shows an end view of a portion of the transmission front support 70 as part of the transmission housing 42. Four

fluid passages

72, 74, 76 and 78 are formed in the front support 70. Each channel extends radially away from the centerline 50 at the same axial location. The four channels are circumferentially spaced from one another. These four passages are used to deliver fluid to and from various locations in the torque converter 18, as described below with reference to

sections

4, 5, and 6.

Fig. 4 shows a fluid path for supplying fluid to hydraulic chamber 52. The idler support shaft 80 is a hollow shaft fixed to the front support 70. A hollow insert 82 is secured to the interior of the idler support shaft 80. The pump impeller 40 is supported for rotation about the idler support shaft 80 by a bearing or bushing 84. The one-way clutch 48 has an inner race 86 fixed to the stator support shaft 80 and an outer race 88 fixed to the stator 46. The turbine shaft 22 is supported for rotation relative to the idler shaft by a bearing 90 and is supported for rotation relative to the input shaft 16 by a bearing 92.

Grooves are formed into the inner surface of idler shaft 80 and/or the outer surface of insert 82 to form an axial passage 94 that connects to radial passage 78. The axial passage continues through the bore 96 in the insert into the space between the insert and the turbine shaft 22. Fluid is supplied through the valve body between the radial passage 78, the axial passage 94, the bearing 90, and into the hydraulic chamber between the one-way clutch 48 and the turbine 44. Another groove is formed into the inner surface of idler shaft 80 and/or the outer surface of insert 82 to form an axial passage 98 that connects to radial passage 72. Fluid exits the hydraulic chamber between the one-way clutch 48 and the impeller 40 through a hole 100 in the stator support shaft 80. The fluid then flows back to the valve body through the axial passage 98 and the radial passage 72.

Fig. 5 illustrates a fluid path for delivering pressurized fluid to the apply chamber 58 of the bypass clutch 54. Another groove is formed into the inner surface of idler shaft 80 and/or the outer surface of insert 82 to form an axial passage 102 that connects to radial passage 74. Fluid flows from the passage 102 through the bore 104 into the space between the insert 82 and the turbine shaft 22 and between the

seals

106 and 108. The hollow insert 110 is fixed to the inside of the hollow portion of the turbine shaft 22. The space between the insert 110 and the turbine shaft 22 forms an axial passage 112. The fluid flows through the bore 114 in the turbine shaft 22, through the passage 112, and then through the bore 116 into the space between the turbine shaft 22 and the input shaft 16 and between the

seals

118 and 120. The fluid then continues through the aperture 122 into the application chamber 58. When the piston 60 is forced into the disengaged position, fluid flows back into the valve body through the same series of passages.

Fig. 6 illustrates a fluid path that conveys fluid between the balance chamber 64 of the bypass clutch 54 and the front support 70. Another groove is formed into the inner surface of idler shaft 80 and/or the outer surface of insert 82 to form an axial passage 124 that connects to radial passage 76. The passage 124 is connected to the space between the

seals

108 and 128 through a hole 126. The interior of the hollow insert 110 forms an axial passage 130, the axial passage 130 being connected to the space between the

seals

108 and 128 by an aperture 132. The end of the passage 130 is connected to the balance chamber 64 through an aperture 134.

In some embodiments, the radial passage 76 may be supplied with low pressure fluid by the valve body. In other embodiments, the balance chamber may be filled with fluid via an aperture between balance chamber 64 and hydraulic chamber 52. The orifice has a size that causes a low flow rate. As the piston 60 strokes, fluid must flow out of the balance chamber 64 relatively quickly without a significant increase in pressure. The path shown in fig. 6 allows fluid to flow out quickly. Fluid may be delivered from the radial passage 76 to a high level drain port in the transmission and from there to the oil pan. By raising the drain, the passage remains filled with fluid when the vehicle is shut off and the transmission pump is not running. When the piston destrokes, the fluid contained in this path quickly flows into the balance chamber 64.

While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. As previously mentioned, features of the various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments may have been described as providing advantages or being preferred over other embodiments or prior art implementations in terms of one or more desired characteristics, those of ordinary skill in the art will recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes, depending on the particular application and implementation. Accordingly, embodiments described as less desirable in one or more characteristics than other embodiments or prior art implementations are not outside the scope of the present disclosure and may be desirable for particular applications.

Claims

1. A transmission, comprising:

the torque converter comprises a pump impeller, a turbine and a guide wheel;

a front support defining a first fluid passage, a second fluid passage, a third fluid passage, and a fourth fluid passage;

a hollow guide wheel shaft fixed to the front support;

a one-way clutch having a first race fixed to the guide pulley shaft and a second race fixed to the guide pulley;

a hollow idler shaft insert secured to an interior of the idler shaft, the first fluid passage fluidly connected to a gap between the idler shaft and the idler shaft insert;

a hollow turbine shaft drivably connected to the turbine and extending through the guide axle insert, the second fluid passage fluidly connected to a gap between the guide axle insert and the turbine shaft;

a hollow turbine shaft insert secured to an interior of the turbine shaft, a third fluid passage fluidly connected to a gap between the turbine shaft and the turbine shaft insert, and a fourth fluid passage fluidly connected to the interior of the turbine shaft insert.

2. The transmission of claim 1, wherein the four fluid passages are located at the same axial position and circumferentially spaced relative to an axis of the turbine shaft.

3. The transmission of claim 1, further comprising a bypass clutch configured to selectively connect the impeller to the turbine, the bypass clutch defining an apply chamber fluidly connected to the third fluid passage and defining a balance chamber fluidly connected to the fourth fluid passage.

4. The transmission of claim 3, further comprising a valve body configured to supply transmission fluid to the torque converter via the second fluid passage and to receive transmission fluid from the torque converter via the first axial fluid passage.

5. The transmission of claim 4, further comprising a clutch assembly configured to selectively connect the impeller to the turbine, wherein the clutch assembly defines an apply chamber fluidly connected to the third fluid passage and a balance chamber fluidly connected to the fourth fluid passage.

6. The transmission of claim 5, wherein the fourth axial fluid passage is fluidly connected to the high-elevation exhaust port.